Positive displacement pumps deliver a discrete volume of pumped fluid during each stroke or cycle of operation. As such, positive displacement pumps are often used for metering or dosing applications. Prior pump systems typically assume a fixed volume of pumped fluid will be delivered during each stroke or cycle of operation of the positive displacement pump. Such systems, however, fail to account for changes in the amount of pumped fluid that will actually be delivered during each stroke or cycle of operation due to variations in back pressure present at a fluid outlet of the positive displacement pump (and/or in the speed at which the positive displacement pump is operated), leading to volumetric inaccuracies.